The subject matter disclosed herein relates generally to positioning systems and methods, and, more particularly, to patient positioning systems and methods that provide patient positioning information relative to one or more predetermined references.
In many, if not all patient related procedures, the patient and/or surgical instruments are positioned in such a way as to provide the best surgical access and outcomes, while minimizing potential risk to the patient. Most patient positions include some degree of risk, and this risk can be amplified in an anaesthetized patient who cannot make others aware of conditions related to their position. In addition, because many patients are transferred and positioned on operating tables in preparation for a variety of surgical procedures, the desired patient position must be reassessed after repositioning.
Because there is a need for accurate patient positioning information, there are systems that are currently available for aiding in patient and/or surgical instrument positioning. These systems require and/or incorporate a dedicated surgical room with dedicated positioning related equipment, which all requires a high upfront cost. These dedicated room systems generally assist a user with determining where in the dedicated room a surgical instrument or patient landmark is located relative to a known fixed point or points in the room, and often require extensive training, dedicated computers, are expensive, and are typically bulky (a whole room), to track a spatial location and/or movement of a surgical instrument or landmark in or on the patient. They frequently require implanted landmarks to operate accurately.
In a variety of orthopedic implant procedures, such as total hip replacement (THR) or arthroplasty, total knee arthroplasty (TKA), high tibial osteotomy (HTO), and total shoulder replacement (TSR), for example, the optimal orientation of the surgical implant can enhance initial function and long term operability of the implant. When dedicated positioning systems are not used, simple “eyeballing” methods or mechanical tools may be used. For example, eyeballing has been used for the alignment of a prosthetic acetabular cup or femoral broach. It has been found that eyeballing is not sufficiently accurate to reliably align and place implant components with the bones to which such components are attached.
One recent study reported on the postoperative complication risk for a THR. One factor identified was the orientation of the acetabular prosthetic cup. The report concluded that malpositioning of the acetabular cup can be linked to many unfavorable clinical outcomes, including increased rate of dislocation of the hip joint, acetabular liner fracture, increased wear, decreased joint motion, joint pain, and hastened failure of the implant. Thus, studies have demonstrated that malpositioning or sub-optimally-positioned orthopedic implants correlates to improper loading, increased implant wear, and even implant failure.
Therefore, correct positioning of the patient before and during a surgical procedure so as to accurately use surgical instruments and place implants, as used in a surgical procedure with respect to the patient's anatomy, is an important factor in achieving a successful outcome.
It would, therefore, be desirable to provide systems and methods that use a small, self-contained device to provide patient specific position information relative to a predetermined reference before and/or during surgical procedures.